346 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



565. G. afiinis (B. & G.) Grd. 



Body moderately stout. Dorsal and anal fins similar in size and 



shape, the latter not much advanced. Coloration plain; dorsal and 



caudal dotted with black. Head 4; depth 3f. D. 6; A. 8. Texas. 



(Girard.) 



{Heterandria affinis B. & G. Proc. Acad. Nat. Sci. Phila. 1853, 390; Girard, U. S. 

 Mes. Bound. Surv. Ichtli, 72 ; Giiuther, vi, 336.) 



566. G. noMlis B. & G."" 



Body very deep, elevated in front of dorsal. Anal much smaller 

 than dorsal. Ventrals very small. Coloration plain. Head 3^; depth 

 3J. D. 8;A. 7. L. 2^ inches. Texas. {Girard.) 



{Heterandria nobilis B. & G. Proc. Acad. Nat. Sci. Phila. 1853, 390; Girard, U. S. 

 Mox. Bouud. Surv. Iclith. 71; GUnther, vi, 335.) 



(Two other species from the Rio Grande region, G. speciosa and G. senilis, are briefly 

 and probably unrecognizably described by Girard, Proc. Acad. Nat. Sci. Phila. 1859, 

 121). 



162.— MOI.LIEWESIA Le Sueur. t 



(Limia Poey.) 



(Le Sueur, Journ. Acad. Nat. Sci. Phila. ii, 1821, 3 : type Mollienesia latipinna Le 

 Sueur. ) 



Body rather stout. Mouth small; mandible very short, its bones not 

 united, the dentary being movable; both jaws with a narrow baud ol 

 small teeth, besides an outer series of long, slender, movable teeth, 

 which are curved and slightly compressed, placed on the outer edge of 

 the jaw. Branchiostegals usually 5. Scales rather large. Anal fin 



* G. gracilis (Heckel) Gthr. 



Anal process twice as long as head; the extremity bent. A dark band from upper 

 end of gill-opening to the caudal. Head 4; depth 4. D. 8; A. 9; scales 29-7. Ori- 

 zaba, Mexico. (GUnther.) 



(Xiphophorus gracilis Heckel, Sitzgsber. Akad. Wiss. Wien, 1848, i, pt. 3, 300; GUn- 

 ther, vi, 33G.) 



tXIPHOPHORUS Heckel. 



(Heckel, Sitzgsber. Akad. Wiss. Wien, 1848, i, pt. 3, 163: type Xipliophoi-us helleri 

 Heckel.) 

 This genus differs from Mollienesia chiefly in the structure of its caudal fin, the lower 

 rays of which in the males are prolonged into a long sword-shaped appendage, which 

 in the adult is sometimes as long as the rest of the fish. Anal of the male modified 

 into an intromittent organ, one or two of the enlarged rays being provided with hook- 

 like processes. Bianchiostegals 5. (|z^o?, sword; ^^opeci), to bear.) 



X. helleri Heckel. 



Sides with blue and yellowish-green bands or dark spots. Prolonged caudal ap- 

 pendage of the male nearly as long as the body, yellow, with black edges. Anal pro- 

 cess with numerous hooks. Head 4^; depth 3|. B. 5; D. 13; A. 9; scales 29-8. 

 Mexico. (GUnther.) 



(Heckel 1. c. ; GUnther, vi, 349.) 



